This invention relates to guards for affixing to the free, open end of a suction tube and, more particularly, to a guard for the open end of suction tubes and high volume evacuators used for ejecting saliva and matter from a patient's mouth during dental procedures.
During certain dental procedures, i.e. procedures which involve the use of modern high speed dental handpieces which eject copious quantities of water for cooling and cleaning, it is necessary to remove the accumulated saliva and matter for effective treatment. This is usually accomplished by the use of a resilient yet flexible suction or ejection tube, the free, open end of which is inserted into the patient's mouth while the opposite end is connected to a source of reduced pressure. To deal with the problem of drawing large debris into the tube and excessive pulling of the soft tissue inside the patient's mouth which may obstruct the tube passageway and cause much discomfort to the patient, guards have been developed which may be inserted over the open end of the tube. Examples of such guards may be seen in U.S. Pat. No. 4,083,115, issued to McKelvey on Apr. 11, 1978; U.S. Pat. No. 2,574,135, issued to Ward on Nov. 6, 1951; and U.S. Pat. No. 3,541,583, issued to Deuschle on Apr. 27, 1967.
Upon inspection, it is seen that the prior art guards all provide a plurality of longitudinally extending radial slots which extend the length of the guard. The annular, proximal end of the guards are telescopically fit over the open end of the suction tube while the distal end tapers inwardly in a direction away from the tube and toward the central, longitudinal axis of the guard and tube to form either a flat or rounded, distal end. The "ribs" which extend from the proximal end to the distal end forming the slots therebetween are typically spaced equally apart from each other and intersect at the central, longitudinal axis of the distal end of the guard to form an "intersection surface" at the distal end with the slots extending from the proximal end to this intersection surface.
During dental procedures, the dentist typically has an assistant standing by to perform saliva ejection on the patient as the dentist works. The suction tube with the guard attached thereto is inserted into the patient's mouth at the locations where the saliva typically accumulates. This may be under the tongue and along the outer gum line of the bottom teeth, between the cheek and teeth. When inserted, the distal end of the guard comes into contact with the soft tissue of the mouth. It is desirous that the suction power of the tube be kept at a minimum operating level such that saliva is effectively withdrawn from the mouth cavity yet the soft, pliant tissues of the mouth are not painfully drawn into the slots of the guard. With the guard thus inserted into the mouth, it is necessary for the assistant to move the tube such that the slot openings come into contact with the saliva to draw it therein since the terminal, distal end of the prior art guards is not open but instead has a surface where the extending "ribs" intersect.
It is therefore a principal object of the present invention to provide a dental suction tube tip guard which provides for maximum withdrawal of saliva and matter entrained therein while the tube is maintained at a suitable, reduced pressure.
It is a further object of the present invention to provide a dental suction tube tip guard which is configured such that the working surface thereof is provided with a maximum open area for passage of saliva and matter therethrough.
It is still another object of the present invention to provide a dental suction tube tip guard which is more efficient in withdrawing saliva and matter from a patient's mouth by providing maximum comfort to the patient through reduced surface area of the guard which permits minimal, required movement of the tube and guard within the mouth.
Other objects will in part be obvious and in part appear hereinafter.